The present invention relates generally to the field of snow-plows and specifically to articulated snow plows. Generally the snow plow system disclosed herein is intended for use on vehicles like trucks, tractors, skid loaders, pick up trucks, sports utility vehicles, etcetera. However, the snow plow system disclosed herein, or at least some aspects of the snow plow system disclosed herein, is also viewed as having application on all types of snow removal vehicles.
Plows with blades that hinge have a number of advantages over plows with straight nonpivotable blades. A lightweight vehicle, carrying a plow cannot easily push deep, particularly hard, or heavy snow with a straight blade. A centrally hinged plow blade or moldboard (sometimes called an apex type plow because the hinge is at the apex of the V formed when the arms or wings of the plow are in a swept back position) allows the operator of the vehicle a greater mechanical advantage since a plow moldboard, with its wings in the swept back V shaped position, will act like a wedge into the snow. Each wing of the plow moldboard acting like an inclined plane depositing the snow to either side of the vehicle. A plow with a straight blade or moldboard also has difficulty in pushing a mound of snow to an out of the way location. Snow will spill out the sides of a plow with a straight moldboard while a hinged plow that can be articulated can have its wings or arms swept forward to form a V-shaped cup like area between the moveable arms of the moldboard. This swept forward position allows for better containment of the snow so that the snow may be moved out of the way without significant spillage.
Unfortunately, despite the many advantages that hinged plows have there are also disadvantages. For example, when the arms of the plow are in the swept forward position the volume of snow that can be moved is somewhat reduced. Additionally, the single center hinge of hinged snow plows can undergo tremendous stress during plowing, e.g., hitting curbs, rocks, or other objects, and thus the single hinge has a tendency to bend or even break after repeated encounters with such objects. Further, many such plows have very complicated designs which make them difficult or expensive to repair.
Additionally, hinged plows are generally not able to trip effectively when they are in the swept back or swept forward positions. This means that hinged plows have difficulty tipping or tilting in response to encountering a solid object like a curb, an elevated portion of the road bed, a manhole cover, etc. This can lead to jarring impacts which are not desirable and which may adversely affect both the structural integrity of the vehicle and the plow. To attempt to compensate for this problem hinged plows are usually provided with extra mass to prevent damage.
However, additional weight or mass can adversely affect the fuel economy, the handling, and/or the structural integrity of the vehicle to which the plow is mounted and does not make the hinged plow trip in a more effective manner.
It is an object of the present invention to produce an articulated plow system having a center section with at least two or a plurality of pivot points (hinge points) instead one pivot point. The system disclosed herein will thus have a moldboard which can articulate. This means that the moldboard will have a plurality of joints or hinge areas about which portions of the moldboard can pivot.
It is a further object of the present invention to provide a pivot between the main frame and the central section of the blade assembly pivot to allow a few degrees of motion about a horizontal axis. The object is to provide a limited amount of float to permit the blade assembly to follow ground contours and allow for some variations in the mounting height of the vehicle mounting points.
It is a general goal of the present invention to produce an articulated plow system, a plow system having at least two or a plurality of joints, having features which overcome the above noted problems and at the same time provide a snow plow having the advantages of a hinged plow and a regular straight plow.
Further, hinged plows, as previously noted, typically have a point, the apex, where the hinge is located. The apex does not have a wearstrip in front of it to contact snow when plowing. Consequently, when a hinged plow is in the position or the swept back position this results in some snow being missed and a trail of unplowed snow being left behind the vehicle. This is not desirable because it requires that the driver make another sweep of the area just plowed to remove the trail of snow left. This wastes both the time and energy of the driver and the vehicle.
Thus, it is a further object of the present invention to provide a center section which can allow for the installation of a center wearstrip in a such a way that the center and wing wearstrips can overlap. Additionally, it is an object of this invention that the center strip be wide enough to accommodate such overlapping but also be narrow enough to allow for free flow of material across the wearstrip and moldboard surface when the blade assembly is angled fully to the right or to the left.
Further, it is an object of the present invention to use a center wearstrip that sufficiently angled with respect to the road or surface to be plowed so that a wedge or chisel affect to provide additional mechanical advantage to break up hard packed snow.
It is a further object of the present invention to include trip springs and pivots mounted to the center section independent of the main frame to allow for float between the main frame and the blade assembly section. Additionally, it is an object of the present invention to provide a center section having a width substantially greater than the single hinge width of apex type plows to provide more stability to the articulated plow system disclosed herein, greater resistance to side loading, and more durability. Further, by increasing the size of the center section more space is provided on the plow body itself for the tripping structure without any compromise to the structural integrity of the plow or its ability to pivot as desired.
It is a further objective of the present invention to permit blade tripping when the articulated plow disclosed herein is in the scoop position; with the wings of the plow swept forward.
It is a further object of the present invention to produce a plow system that may also be used on vehicles that are not well suited to heavy plows or to be used on vehicles where fuel economy is a consideration. Accordingly, the articulated plow blade of the present invention is designed so that it may be lighter in weight than prior art apex type plows.
It is a further object of the present invention to have a self-contained power unit and means of attaching the power unit mounted on the articulated plow and not the vehicle. This has the advantage of requiring less modification to the vehicle upon which the plow will be used. This will also aid in maintaining the center of gravity of the vehicle to help make the vehicle more stable since the majority of the weight added to the vehicle will be as part of the articulated plow located in front of the vehicle generally below the passenger compartment or cab. This allows the weight of the power unit to become an effective weight at the wearstrip rather than being fixed weight at the vehicle which is not desirable.
It is a further object of the present invention to address the problem of excess, performance reducing, weight on hinged snow plows. The present invention includes a reactive controlled pressure system that places a controlled predetermined pressure upon the moldboard of the plow system so that a portion of the weight of the vehicle to which the plow system is attached is actually transferred to the bottom edge of the plow moldboard and the plow moldboard acts as a moldboard weighing 2 to 3 times its actual weight. This allows the articulated plow blade of the present invention to be lighter in weight but to be as effective or even more effective in plowing as a hinged plow system.
It is a further objective of the present invention to provide the flexibility of having, in effect, both a light weight articulated plow (which is advantageous for certain conditions such as plowing light snow on a gravel driveway) and a heavy weight plow (which is advantageous for plowing drifted and hard packed snow and for scraping hard surfaces). This flexibility is obtained by having a reactive controlled pressure system which can be activated and de-activated by means of a simple electric control switch. The controlled pressure mechanism maintains a pressure within a certain predetermined low pressure and high pressure limit with a predetermined nominal pressure within these limits.
It is a further objective of the present invention to provide an articulated plow having a bell crank lift arm combination for lifting the articulated plow.
It is a further object of the present invention to have only a small mounting subframe located beneath the front bumper of the vehicle which is attached to the vehicle frame. All other components of the snow plow system are mounted to this mounting subframe so that they can be easily and quickly removed from the vehicle. Consequently, there is no substantial amount of mounting equipment covering the front end of the vehicle and little added weight permanently attached to the vehicle.
It is a further objective of the present invention to include a quick connecting/disconnecting structure to make it very easy to attach or disengage the snow-plow system from the vehicle. This saves the operator of the vehicle both time and effort when installing and removing the snow plow system.
Further, the present invention addresses the problem of lights mounted to vehicles for plowing. Typically an additional set of headlights and parking lights are mounted to the front end of a vehicle for plowing. This is because the regular headlights and parking lights of the vehicle are usually hidden behind the plow moldboard and thus are obstructed by the plow moldboard especially in the raised position. As such, the lights are rendered ineffective. Consequently it has been the case that an additional set of lights are mounted either upon the hood or up on the front grill of the vehicle so that they project over the front edge of the plow moldboard. The problem with this procedure is that these lights and their housings in and of themselves create obstructions in the driver's field of vision due to the fact that they are mounted on the vehicle. To overcome this problem it has been attempted in the prior art, in straight or traditional plows, to move the lighting system to a position off the vehicle and onto the plow structure itself. The device of the present invention moves these lights off of the vehicle and positions them so that they shine over the top edge of the moldboard, while presenting a minimal obstruction to the field of vision of the driver or operator of the vehicle. Since the additional lights are mounted on the plow and not on the vehicle they are removed when the snow-plow is removed. This eliminates having a second set of lights permanently mounted on the vehicle. Further, it is an objective of the present invention to allow these lights to be mounted to a fixed position or mounted to a telescoping mount so that their position may be independently adjusted.
It is a further object of the present invention to provide a simplified structure for moldboard attachment to an articulated plow system wherein the moldboard is retained to the moldboard structure by a special retaining means that allows for easy replacement of the moldboard.
Finally, it is an object of the present invention to provide a U shaped articulated plow form so that a greater volume of snow can be collected between the wings or arms of the plow. This also makes it possible to contain and control the snow mass better and lends itself to ease of cleaning up the surface area from which the snow is being removed.
The inventors do not know of any prior art that either teaches or discloses the unique features of the present invention.